Polyvinyl pyrrolidone in viscose and method of producing dye-receptive filaments



April 9, 1968 N. E. FRANKS POLYVINYL PYRROLIDONE IN VISCOSE AND METHODOF PRODUCING DYE-RECEPTIVE FILAMENTS Filed-Aug. 14, 1967 vIsCoSEPOLYVINYLPYRROLIDONE VISCOSE SUPPLY SUPPLY SUPPLY h MIXING APPARATUS ISPINNERETTE SPINNERETTE APPARATUS APPARATUS REGENERATING RECENERATINCBATH BATH I I STRETCHING STRETCHING APPARATUS APPARATUS l l PLYING AND ICOLLECTING MEANS PURIFICATION a DRYING I I w CoNvERSIoN YAR INTo FABRICDYEING DYEING I TONE ON TONE TWO COLOR FABRICS INVENTOR. NEAL E. FRANKTS 3,377,412 POLYVINYL PYRROLIDONE IN VISCOSE AND METHOD OF PRODUCINGDYE-RECEPTIVE FILAMENTS Neal E. Franks, Cincinnati, Ohio, assignor toAmerican Enka Corporation, Enka, N.C., a corporation of DelawareContinuation-impart of application Ser. No. 371,840, June 1, 1964. Thisapplication Aug. 14, 1967, Ser. No. 660,250

2 Claims. (Cl. 264-78) ABSTRACT OF THE DISCLOSURE A process for theproduction of regenerated cellulose in the form of textile structuressuch as filaments, fibers and yarns, the combination includingincorporating into a viscose, prior to extrusion thereof, an amount ofpolyvinyl pyrrolidone having an average molecular weight of about360,000 and a K-value between 80-100 in order to permit dyeing with acidor premetallized dyestuffs. The thus modified structures can then becombined with unmodified structures that are only susceptible to thosedyestuffs normally used in dyeing regenerated cellulose in order toobtain a composite textile article of manufacture consisting ofpolyvinyl pyrrolidone modified textile structures and unmodifiedstructures that are especially suitable for multicolored effect dyeingwhen utilizing a single dyebath and containing at least two distinctclasses of dyestuffs, i.e., the above-mentioned acid or premetallizeddyes and direct or substantive dyes.

SPECIFICATION This invention relates to the production of textilestructures consisting of regenerated cellulose such as yarns, filaments,fibers or the like as well as fabrics made therefrom which haveremarkable dyeing properties with respect to the acid and/orpremetallized dyestuffs. This application is a continuation-in-part ofapplication Ser. No. 371,840 filed June 1, 1964, commonly assignedherewith now abandoned.

It is known that the various kinds of cellulose-containing textilestructures such as filaments, fibers, yarns, ribbons and/ or tow aregenerally non-receptive to the acid and premetallized dyestuffs commonlyused to dye nitrogen-containing woolen, synthetic nylon, or acrylicfilaments, fibers and yarns as well as ultimate textile fabric productsmade therefrom. It is also known that numerous processes have beenproposed in an effort to increase the affinity of such structures forthe dyestuffs and many generally embrace treatments with variouschemical agents after they are shaped or converted into end productssuch as fabrics and the like. It has also been proposed to includevarious organic compounds in a spinning solution to produce uniformlymodified structures that are readily susceptible to dyeing with acid orpremetallized dyes throughout a given cross-section. Compounds which theprior art teaches that can be uniformly incorporated in spinnablesolutions or compositions include, for example, the polyalkylene amines,polyalkylene imines, various urea derivatives, basic condensationproducts from phenol, formaldehyde, aliphatic monoor diamines, reactionproducts of halogenated aliphatic or aromatic hydrocarbons, esters,ketones, polymerizates, etc. The compounds, when added to spinnablecompositions such as viscose or the like, increase the affinity of thestructures for acid and/or premetallized dyestuffs in some degreealthough, with most, serious practical disadvantages exist.

In using the known compounds it is found that they States Patent causeeither fabric stiffness or the acid or premetallized dyestuffs are notsufficiently stable to the effects of wet treatments, for example, tothe effects of washing, bleaching, mercerizing, dry cleaning,perspiration and the like. The acid and/ or premetallized dyestuffs areeasily leached out and, in general, textile fabrics containing such dyeslack the wash or light fastness required to compete commercially with amaterial which, for example, has been printed or dyed with a more stablebut less brilliant direct or substantive type dye.

In the case wherein known dye improving additives are merely impregnatedon the fabric, a time consuming and expensive post-treatment of thematerial has been found necessary to increase the retention of theadditives and consequently the dye in final products. Uniformity ofadditive impregnation with a resulting uniformity in dyeing of theproducts throughout their crosssection is difficult to accomplish whenadditives are incorporated with textiles in this way and, additionally,many inhibitors or improvers are unsatisfactory in that they also impairthe chemical and physical properties of the yarns and finished textileproducts containing the yarns. Fabrics treated by post-treatment and thelike also lose strength and tend to fade quickly when exposed toultraviolet light.

Many of the compounds included in spinnable rayon compositions alsodeleteriously affect the chemical and physical properties of structuralproducts formed therefrom, notwithstanding the fact that many of thosewhich are known are not sufficiently soluble in the composition andtherefore are not readily and uniformly intermixed throughout theproducts.

In accordance with the invention, it surprisingly has been discoveredthat by physically admixing or treating cellulosic spinning compositionswith a certain readily available polymeric material of extremely highmolecular weight heretofore thought impractical because of the materialsinherent water solubility characteristics, textile structures can beformed which not only have a high affinity for acid dyes andpremetallized dyes closely resembling that possessed by wool and thenitrogen-containing synthetics but also avoid the disadvantages notedabove. Equally surprising, it has been found that by modifying thecellulosics with the novel compound (identified hereafter) an affinityfor those dyestuffs normally used in dyeing such materials, e.g., thedirect or substantive dyes, is noticeably improved.

It is, therefore, an object of this invention to provide deeper and moreuniformly dyed viscose fibers and yarns not having the aforementioneddisadvantages.

Another object of this invention is to provide a process for increasingthe afiinity of viscose fibers and yarns for dyes, more specifically theacid and premetallized type dyes.

Still another object of this invention is to provide a modifiedfiber-forming viscose solution that will increase the action ofconventional viscose treating dyestuffs and easily accept acid andpremetallized dyes.

An additional object of this invention is to provide a process forobtaining a uniform dispersion and retention of the dye-influencingadditive throughout the viscose fibers and yarns.

These and other objects will become apparent from the following detaileddescription.

In accordance with one embodiment of the invention and in its broadestaspect, regenerated cellulose fibers and filaments can be modified topossess an increased afiinity for certain dyes by incorporating into aregenerated cellulose solution, such as viscose, prior to filament orfiber formation a small amount of high molecular weight polyvinylpyrrolidone (hereinafter referred to as PVP). Now,

for the first time, regenerated cellulose textile structures can beproduced that have a remarkable increased and lasting aflinity for thosedyestuffs normally used in dyeing the nitrogen-containing natural orsynthetic filaments, fibers and yarns. Furthermore, the dyestuffs, i.e.,acid and premetallized dyes, do not migrate or wash out when subjectedto severe wash tests and evaluations.

While not wishing to be bound by theory, it is believed that theaddition of the PVP to the viscose stream increases the number of dyesites available in the extruded filament for the attachment of thepremetallized or acid dye molecules and the PVP is held in theregenerated cellulose by an attraction or bonding between the PVPmolecule and hydroxyl hydrogen atoms of the cellulose molecules althougha positive cross-linking or chemical reaction does not appear to takeplace to any appreciable extent between the polymer molecules. In anyevent, when the PVP is homogeneously mixed in the viscose solution,resulting shaped products are found to be quite stable to the etfects ofwashing, caustic treatments, etc., and will not be decomposed under thenormal uses to which such regenerated cellulosics are subjected. Dyedtextile products containing PVP in particular are similarly stable whensubjected to such treatments and, perhaps even more surprising in viewof that which is known, the PVP containing products dyed with direct orsubstantive dyes also show improvements in relation to depth of colorand stability.

The high molecular weight PVP is a readily available material and may beincorporated into the viscose solution in a number of ways. For example,it may be mixed batch-wise or it may be added directly to the flowingstream prior to spinning by a method such as that shown by Patent No.2,934,448 to T. E. Patton. The exact method used to effectively mix thesolutions is not critical, as long as a homogeneous dispersion of thePVP in the viscose is accomplished. By addition prior to spinning, ahigh degree of retention of the PVP in. the final fiber is believedaccomplished due to the unusual hydrogen bonding previously mentionedwhich prevents subsequent loss of the dye in normal washings of the dyedfabric. Further, the addition prior to spinning also allows a moreuniform distribution of the PVP throughout the entire fiber product,thus in effect creating a more uniform coloring in the textile material.

The amount of the high molecular weight PVP added to the fiber-formingviscose solution can be varied, depending on the results desired.Amounts less than about 2% by weight PVP based on the weight of thecellulose in the viscose solution (CIV) are not generally sufficient toproduce the degree of effect desired. It is preferred that amounts below6% be used since greater amounts have been found to cause difficultiesin spinning and processing of the viscose solution prior to fiber orfilament formation. Preferably, amounts of PVP ranging from 2% to areemployed in the process. In general, the molecular weight of thepolymeric vinyl pyrrolidone to be employed may range from about 200,000to 400,000 or higher. Optimumly,,it is preferred that the averagemolecular weight be approximately 360,000 as determined by appropriateviscosity measurement techniques.

Spinning procedures and equipment customarily used in production ofviscose fibers, including conventional spinbath, can be used with thePVP-modified viscose and the fiber product may be processed into yarn byany known means. The attached figure shows a schematic representation ofone particularly suitable procedure for forming composite yarns of theinvention. Modified and unmodified filament bundles can either becombined immediately after precipitation of the viscose in spinbath orthey can be combined immediately before collection in a suitable package(spool or cake). Combining immediately after spinning results in aheather coloring effect in the yarns, i.e., a random blending of onecolor into another, caused by filament placement, while combining theyarns immediately before collecting into a package results in a distinctcontrasting two-color effect when two distinct color producing dyestuffsare used, or, alternatively, a contrasting two-tone effect when aone-color producing direct dyestuff is used.

It should be understood that the modified yarn can be crosswoven withuntreated viscose yarns into fabrics or tufted into carpets and, whendyed with a direct dyestuff of a single color using standard procedures,a striking two-tone wash fast color effect is achieved in the finishedproduct. Dyeing with dyes of two distinct color, i.e., one acid orpremetallized and one direct, will give a two-color effect in thefabrics or carpets.

It also should be understood that several yarn bundles containing thePVP can be combined with like yarn bundles which do not contain theadditive to form a composite tow which facilitates composite staplefiber manufacture. The tow can be cut into fibers of preselected lengthaccording to known practices. It will be appreciated that the staplefibers can be manufactured from solely PVP-containing yarns andthereafter spun with synthetic staple, e.g., nylon, polyester oracrylic, to produce yarns having distinct multicolored characteristicswhen woven into fabrics; or, composite regenerated cellulose fibers (PVPmodified and unmodified) can also be spun with synthetic staple fibersto produce fabrics having an even further increased multicoloringcapacity.

For purposes of illustration, the following examples are given, However,the invention is not intended to be limited thereby. Unless otherwiseindicated, percentages are given in percentages by weight.

Example I A fiber-forming viscose solution, prepared by conventionalxanthation of alkali cellulose, followed by the usual treatment withdilute sodium hydroxide, was combined with a 20% aqueous solution of PVP(a clear viscous aqueous solution of polyvinyl pyrrolidone sold byGeneral Aniline & Film Corporation, New York, N.Y., under the name K-and having an average molecular weight of about 360,000) at 49 F. toproduce a resulting batch mixture containing 2.5% PVP-CIV (cellulose inviscose). The mixture was agitated for one-half hour to disperse anddissolve the PVP throughout the viscose. The result- 5 ing mixture wasdeaerated overnight at 63 F. and spun into an acid spinbath containing4.6% sulfuric acid, 11.9% sodium sulfate, and 3.75% zinc sulfate(percentages by weight of the spinbath). The temperature of thisspinbath was held at 108 F. The resultant filaments were washed andgiven normal post-treatment.

Example II A viscose solution prepared as in Example I was injected witha 5.0% aqueous solution of PVP. The injection was made directly into theviscose stream and mixed according to the process defined by theaforementioned Patent No. 2,934,448. The final composition spuncontained 2.5% by weight PVP to the CW. The composition was spun into aspinbath containing 11.2% sulfuric acid, 5.1% magnesium sulfate, 17.45%sodium sulfate, and 1.0% zinc sulfate, and the extruded filament wasthen conventionally purified and dyed.

Example III A skein composed of the viscose prepared by the process ofExample II and an untreated viscose skein were scoured with Rohm & HaasTriton CF 10, 0.2% (a benzyl ether of an acetylphenol-ethylene oxideadduct) and 0.5% tetrasodium pyrophosphate at 180 F. for 20 minutes.After rinsing, the skeins were placed in a 1.0% Triton CF 10 bath at F.for ten minutes. The temperature of the bath was raised to 200 F. and0.5% of Du Ponts Alkanol HCS (a non-ionic surfactant) and 0.3% ammo- V.A unique two-color effect was produced in the material.

TABLE IMODIFICATION DATA carpet Polymer Identification, Proper- Spinbathties and Concentration in Viscose Examples (Sample) K- Avg. Temp. Ident.Value gives. Con. Composition F.)

VII K- 15-21 10,000 2.5 Aqueous solution containing: 108

4.6% H2804, 11.9% NazSO-l, 3.75% Z11S04. VIII K 26-35 40,000 2.5 do 108I K430... 5062 160, 000 2. 5 108 X K90 80-100 360,000 2. 5 108Aftertreatment Dyeing Examples Percent Temp. Remarks (Sample) Wash-Bleach- Polymer Type 2 of Dye- Time ing ing Remainbath (min.)

ing 1 F.) VII Yes Yes 0. 01-0. 10 AB 200 45 Fabric only stained. VIIIYes Yes 0.01-0.10 AB 200 45 Do. IX Yes Yes. 0.01-0.10 AB 200 45 Do. XYes Yes. 2. 5 AB 200 45 Excellent color (i0. 10. 2) quality.

1 Percent polymer weight based on CIV.

2 Dye Ty e and the skeins allowed to remain for 45 minutes. The skeinswere then removed, rinsed and dried. A slight staining of the untreatedskein was accomplished which immediately washed out, while the treatedskein showed a deep blue color.

Example IV Skeins of treated and untreated viscose yarns were preparedand scoured in the same manner as Example III. The skeins were thenadded to a solution containing 0.5% Triton CF 10 and Geigy ChemicalsErional NW 2.0% (a mixed condensate of naphthalene mono-sulfonic acidwith dihydroxy diphenylsulfones and formaldehyde) at 115 F. and allowedto remain for 10 minutes. The treating bath was then heated to 200 F.,15% sodium chloride was added, and a premetallized dye consisting of0.5% CI Acid Red 182 was added. After 45 minutes, the skeins wereremoved, rinsed and dried. A slight staining was observed on thenontreated skein while the treated skein was a deep red.

Standard wash fastness tests were performed on the dyed skeins withfavorable results and light fastness tests showed no appreciable loss inthe treated skein under prolonged exposure. Secondary swelling valuesand strengths of the treated and untreated skeins showed no appreciablechange.

Example V A knitted fabric composed of treated and untreated yarns wasscoured and pretreated with Triton CF 10 and Erional NW as in ExampleIV. To the resulting solution was added a mixture of premetallized anddirect dyestuffs consisting of Ciba Chemical & Dye Companys CibalanBrilliant Blue RL 5.0%, Organic Chemical Corporations Orcolite FastYellow EFL 0.3%, and General Dyestuff Companys Fastusol Blue FL 3 GL0.6%. After 45 minutes at 200 F. the knitted fabric was removed andrinsed. The resulting treated fabric produced a two-color efiectconsisting of deep blue and green. Standard light fastness and washfastness tests showed no significant loss in the treated yarn portionscompared to the untreated yarn portions of the fabric.

Example VI A tufted carpet material produced by combination of theregenerated cellulosic fibers treated with PVP and such nontreatedfibers was dyed according to Example Examples VIIX The above samples inthe table clearly show that the K-90 modified yarns will not solubilizein any appreciable amounts when used according to the invention and,moreover, will have a much improved dye affinity over the standardviscose yarns when treated with lower molecular weight polymer underidentical conditions.

The Kvalue (Fikentscher) of any particular mixture of polymers iscalculated from viscosity data and is useful as an indication of theaverage molecular weight of such mixture. Its determination is fullydescribed in Modern Plastics, 23, No. 3, 157-61, 212, 214, 216, 218(1945) and is defined as 1000 times k in the empirical relativeviscosity equation:

ic "reel 75102 C l+1.5kC'

wherein C is the concentration in grams per hundred cc. of polymersolution and a is the ratio of the viscosity coefficient in order toavoid the use of decimals. For the purpose of the present inventionthere may be employed polymeric N-vinyl pyrrolidone having a K-value of200, preferably of 80 to 100, and having an average molecular weight ofabout 360,000.

What is claimed is:

1. A fiber-forming composition of matter comprising a major amount ofviscose including a wash-fast and lightfast dye improving quantity of atleast about 2% by weight of polyvinyl pyrrolidone based on the weight ofcellulose in said viscose, said polyvinyl pyrrolidone being of averagemolecular weight of about 360,000 and having a K-value of approximately8090.

2. A process for the preparation of multifilament yarns of regeneratedcellulose having a wash-fast and light-fast afiinity for acid and/ orpremetallized dyestuffs comprising in combination:

(a) homogeneously including into a viscose solution prior to extrusion,at least about 2% polyvinyl pyrrolidone based on the weight of cellulosetherein, said polyvinyl pyrrolidone being of average molecular weight ofabout 360,000 and having a K-value of approximately 8090,

(b) extruding the thus modified viscose through a spinneret to form aplurality of continuous filaments in at least one acid coagulating andregenerating bath,

References Cited UNITED STATES PATENTS Watson 8-15 Bock et a1 815 Geigy8-85 Benneville et a1. 26017 Stoner et a1. 260-17 Howsrnon 264194Mautner 885 Walles et a1. 260--17 OTHER REFERENCES Schildknecht Vinyland Related Polymers, 1952, TP986 V4853, pp. 676 and 677.

JAMES A. SEIDLECK, Primary Examiner.

A. KOECKERT, Assistant Examiner.

